Corrugating single facer



April 11, 1961 H. w. WILSON 2,979,112

CORRUGATING SINGLEFACER Filed Sept. 9, 1957 2 Sheets-Sheet 1 INVENTOR.

April 11, 1961 H. w. WILSON CORRUGATING SINGLE FACER 2 Sheets-Sheet 2 Filed Sept. 9, 1957 R O T N E V m CORRUGATJNG SINGLE FACER Harry W. Wilson, 301 Elder Ave., Millbrae, Calif.

Filed Sept. 9, 1957, Ser. No. 682,699

6 Claims. (Cl. 154-31) This invention relates to improvements in a corrugating single facer.

A corrugating single facer is a machine for corrugating one strip of paper and applying a flat strip to one face thereof so as to provide single-face corrugated paper. To do this, one strip of paper from a large roll may be fed between a pair of corrugating rolls. This strip of paper is known as the corrugating medium, because the corrugating rolls impose a corrugated pattern upon it. The corrugating medium is then carried by one of the corrugating rolls around to a station where it is glued to an uncorrugated strip of paper known as the liner. Between the nip where the two corrugating rolls corrugate the medium and the nip where a smooth roller applies the liner, an adhesive material (glue) is applied to the tips on one side of the corrugating medium, and this is the adhesive that glues the liner and the corrugating medium together.

Problems have arisen in this type of operation because the nipping contact between the liner and the corrugating medium is very brief. In the prior art devices there is contact between the medium and liner only at the nip where the liner is applied, the nip being between the corrugating roll and a pressure roll. This pressure roll is loaded by air, liquid, or springs to give a rather high nipping pressure, but the nipping action lasts only for between about of a second and of a second. It often happens that the liner paper has been given somewhat too much surface sizing; if so, the adhesive will not penetrate the fibers of the liner and will instead be squeezed onto the sides of the corrugations, Where it has very little effect. In fact, the only adhesive that has value is that between the tip of the corrugating medium and the liner. The parts that are squeezed out to the edges of the flutes that bridge the liner are of little value because there is no fiber pull there. To get a satisfactory bond it is necessary for a certain amount of adhesive to penetrate into both the medium and the liner at the corrugating tip point, and that is precisely where the prior art has failed to give good results. As a result of this failure a considerable amount of single-face corrugation paper has been unsatisfactorily bonded and has had to be discarded. This waste is very expensive and is a major problem in the industry.

The'present invention solves this problem. It does this by a novel arrangement and construction of rolls wherein the liner is fed into contact with the corrugating medium after the application of the adhesive to the corrugating medium but over a considerable arc before reaching the pressure roll. This gives a greatly increased time of contact, of the order of 100 to 200 times as long, and means that when the nip is reached at the pressure roll, the adhesive has been given a longer period to penetrate and is therefore able to act more effectively. The invention thus greatly reduces the amount of singleface corrugated paper that must be discarded because of poor adhesion.

States ate- 2,979,112 Patented Apr. 11, 1961 Other objects and advantages of the invention will appear from the following description of a preferred embodiment thereof in connection with a brief illustration and illustration of the prior-art situation, because this invention is not easily understood without first understanding exactly what the difiiculties were in the prior-art structure.

In the drawings:

Fig. 1 is a view in elevation and in section of the major part of the corrugating single facer machine embodying the prior-art construction.

Fig. 2 is a view similar to Fig. 1 of a corrugating single facer embodying the principles of the present invention, taken along the line 2-2 in Fig. 3.

Fig. 3 is a view taken looking in the direction of the arrow 3 in Fig. 2.

Fig. 4 is an enlarged view of a portion of Fig. 2.

Consider first the prior-art structure shown in Fig. 1. A corrugating medium 10 is fed between two corrugated surfaces 11 and 12 of respective rolls 13 and 14. The roll 13 rotates about an axis 15 while the roll 14 rotates about an axis 16. corrugations are formed in the medium 11) at a nip 17, which lies along the plane 18 connecting the axes 15 and 16. After corrugating the medium 10 is held against the corrugated surface 12 of the roll 14 by a plurality of fingers 20. The fingers 20 are usually approximately & thick and are spaced about two or three inches apart across the face of the roll 14. Their primary purpose is to hold the corrugating medium 10 in contact with the corrugated surface 12 at all times except at the point where the medium 10 picks up the adhesive from an adhesive-applying roll 21.

The adhesive-applying roll 21 rotates about an axis 22 at approximately to the plane 18. In other words, the plane 23 connecting the axes'22 and 16 lies at about 90 to the line 18. This is not a critical factor, and the angle may be greater or less than 90, but approximately that is normal. The roll 21 picks up adhesive from a well below it, and a doctor roll 24 located at one side of the adhesive-applying roll 21 meters the amount of adhesive carried on the surface of the roll 21 and transferred to the tip of the corrugations on the medium 10. At the point where the plane 23 crosses the fingers 20; in other words, at What would be the nipping point of the rolls 14 and 21, if they met; the fingers 20 are provided with a slight relief known as the fluif point, and at this point the corrugating medium 10 dips down and rides the surface of the adhesive! applicating roll, thereby applying the adhesive to the tips of the corrugation.

From there the corrugating medium 10, with the adhesive on its tips, rides around the corrugating roll 14 until it comes to the pressure roll 25. The pressure roll 25 is urged by springs or by hydraulic or pneumatic means toward the roll 14 with a pressure normally between 75 pounds to pounds per lineal inch of the roll width. The roll 25 rotates about an axis 26 and the plane 27 connecting the axes 16 and 26 will, in the conventional machine, always be located on the same side of the axis 18 as the adhesive-applying roll 21. If it were beyond the axis or along the axis 18 the fingers 20 would have to be in two pieces, and this is not usually the practice. The nip 28 lies, of course, along the plane 27.

A liner 30 is fed around a floating idler roll 31 across 7 to the roll 25 and from there around it to the nip 28. At the nip 28 the pressure is supposed to cause the adhesive, which has been applied to the tips of the corrugated medium 10, to adhere to the liner 3%). But the contact area is so short and the time of duration is so very short and-it may be as long as .01 second or as little as .001 second-that if the liner 30 happens to be somewhat more heavily surface-sized than it should be, the adhesive fails to penetrate and is squeezed out from the tips and spread to the front and back of the flutes that bridge the liner 30, leaving very little adhesive on the important tip contact area. The adhesive that is squeezed out has no fiber pull and therefore has no substantial adhesive binding. It is necessary, in order to get a good bond, for a certain amount of the adhesive to penetrate into both the liner 30 medium 10. i

and the corrugating In between the nip 42 and the nip 44 the liner 30 itself acts as a. supporting agent between the rolls 25 and 40, instead of having fingers like the fingers 35 or 20. It is obvious that the liner 30 would tend to travel in a straight line between the nip 42 and the axis line 45, but it is deflected by the curvature of the corrugating roll 14, and

There are, of course, other refinements in prior-art .T

machines, but they do not relate to the problem that has just been considered, and in order to simplify the explanation of the invention they can be left without further description. I now pass to a description of the present invention.

In the present invention the corrugating medium 10 is 7 fed between the corrugated surfaces 11 and 12 of the rolls '13 and 14, as before, and the relationships of the axis 15, the axis 16, the plane 18 connecting them, and the nip 17 is also the same as before. There are fingers 35' which are substantially identical to the fingers 20 except that they do not extend as far around the periphery of the roll 14, for reasons that will soon become apparent. There is, again, the adhesive roll 21 and the doctor roll 24, but the axis 36 of the adhesive roll 21 may be moved slightly closer to the nip 17 than before, placing the plane 37 connecting the axes 36 and 16 at less than a right angle with respect to the plane 18. This is not absolutely necessary but is advisable for a reason which will also be seen soon. The liner 30 is fed over the idler roll 31 as before but is not fed directly from there to the roll 25. Moreover, the roll is displaced along an axis 38 to a different location, as will be seen in a moment.

The outstanding feature of the new invention is the provision of an additional roll 40, which may be called an initial contact roll Where the liner is mated with the corrugating medium 10 before application of nipping pressure. The roll 40 has a smooth face, is mounted on an axis 41, and the nip 42 is on the plane 43 connecting the axes 16 and 41. At the nip 42 a clearance is provided instead of a pressure nip, and the minimum clearance equals substantially the caliper of the combined materials, which may be between .025" to .030", or the opening may be several times the minimum caliper of the combined materials. The roll 40 is therefore made adjustable along the plane 43. At this point, then, the liner 30 is fed into contact with the corrugating tips without any tendency at this point to impose a squeegee acapplying roll 21 with the axis 17 of the second corrugat- I ing roll 14. This is advisable. The actual position may be between 180 and 300 in a counter clockwise direction relative to the plane 18, as distinguished from the angle of less than 180 which was necessary in the prior art with a one piece finger. (See Fig. 1.) This obviously gives a considerable area of the arc during which the liner 30 and corrugating medium 10 are in contact before they reach the nip 44. Between the roll 40 and the roll 25 is mounted a liner guide 46 which is a curved, arcuate member simply serving to guide the liner 30 into position at the nip 44 and exerting no other pressure on it. Its principal use is when the free end of the liner 30 is first entered into the machine.

the pressure that can be exerted by the liner 30 toward the medium 10 can be controlled by the tension applied on the liner 30.

Since the adhesive comes into contact with the liner 30 with much easier action and with less tendency for squeegeeing and since the. contact between the liner 30 and the tips on the medium 10 lasts for a greater time interval before actually entering into the pressure nip between the rolls 14 and 25, greater penetration of the adhesive into both the medium 10 and the liner 30 is possible. Therefore, the bond is greatly superior to what was possible in the prior art.

Thus, operation of the invention may be summarized by stating that the corrugating medium 10 is corrugated at the nip 17 between the rolls 13 and 14, has adhesive applied to the tips of the corrugations by the adhesiveapplying roll 21 and then is faced with the liner 30 at the nip 42 of the roll 40. From there it is carried by the corrugated surface 12 of the roll 14 to the nip 44 between the rolls 25 and 14, this nip 44 lying on the opposite side of the plane 18 from the adhesive-applying roll 21. The glue which-was applied to the corrugated tips by the roll 21 meets the liner 30 early and during the entire arc of rotation between the nips 42 and 44 has a chance to penetrate the surface of the corrugated tips and of the liner 30. The final pressure is applied at the nip 44 and acts to hold the paper sheets together. Considerable heat is usually present at these times to aid this action.

In addition to the longer penetration period of adhesive, anotherbenefit is derived. Because of the longer curvature of contact of the corrugating medium 10 with the roll 14 and because the medium 10 is fully supported by the liner 30, which itself is a semi-insulating material, over quite an angular area of the roll 14, the corrugating medium 10 has a longer curing period.

To those skilled in the art to which this invention relates, many changes in construction and widely diifering embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

I claim:

1. In a paper corrugating system wherein a corrugating medium is fed between two corrugating rolls and then around the surface of one roll, adhesive being applied to the tips of the corrugations on the outer surface thereof by an adhesive-applying roll, the combination therewith of: a paper-liner-applying roll adjacent and beyond said adhesive-applying roll and spaced away from said one roll but closely adjacent to it, said paper-liner-applying roll being mounted in such manner that no nip pressure is applied to said liner by said paper-liner-applying roll and said one roll when said liner is fed between them, wherein in a liner sheet is fed into unpressnrized contact with the tips of the corrugations between the linerapplying roll and the corrugating roll upon which the corrugating medium is being carried; and a pressure-applying roll at an angular position lying beyond the linerapplying roll for applying pressure to the liner and cormgating medium to firmly adhere them together, the time interval between the application of the liner to the corrugating medium and the nip of the pressure-applying roll against the corrugating roll serving to aid the penetration of the adhesive into the paper members.

2. vThe combination of claim 1 wherein the minimum clearance between said liner-applying roll and the adjacent corrugating roll is at least as great as the caliper of the combined liner and corrugating medium.

3. The combination of claim 1 wherein there is an arcuate liner guide between said liner-applying roll and said pressure-applying roll exerting no substantial pressure on said liner and corrugating medium but guiding them.

4. In a paper corrugating system wherein a corrugating medium is fed between two corrugating rolls and then around the surface of one roll, while adhesive is applied to the tips of the corrugations on the outer surface thereof by an adhesive-applying roll, and is then fed between the corrugating roll and a pressure-applying roll, the combination therewith of: a paper-liner-applying roll between said adhesive-applying roll and said pressure-applying roll spaced from and closely adjacent to said one roll, said one roll being mounted in such manner that no nip pressure is applied by said one roll and said paper-liner-applying roll to said liner when said liner is' fed between them wherein a fiat liner sheet is fed into unpressurized contact with the tips of the corrugations between the liner-applying roll and the corrugating roll upon which the corrugating medium is being carried, the time interval between the application of the liner to the corrugating medium and the nip of the pressure-applying roll against the corrugating roll serving to aid the penetration of the adhesive into the paper members.

5. A paper corrugating system, including in combination two corrugating rolls between which a corrugating medium is fed at a nip and an adhesive-applying roll 6 i adjacent said one roll and about past said nip where adhesive is applied to the tips of the corrugations on the outer surface thereof; an unpressurized paper liner-applying roll adjacent and spaced from said one roll and beyond said adhesive-applying roll and less than past said nip, said paper-liner-applying roll and said one roll being so mounted relatively to each other that no nip pressure is applied by them to said liner when said liner is fed between them wherein a liner sheet is fed into unpressurized contact with the tips of the corrugations between the liner-applying roll and said one roll; and a pressure-applying roll more than 180 beyond said nip for applying pressure to the liner and corrugating medium to firmly adhere them together, the interval between the application of the liner to the corrugating medium and the nip between the pressure-applying roll and said one roll serving to aid the penetration of the adhesive into the paper members.

6. The system of claim 5 wherein the pressure-app1ying roll lies between 180 and 300 from the nip between the two corrugating rolls.

References Cited in the file of this patent UNITED STATES PATENTS Bauer Dec. 21, 

